Unless otherwise indicated herein, the description in this section is not prior art to the claims in this application and is not admitted to be prior art by inclusion in this section.
There is known an image forming apparatus, such as a printer and a digital multi-functional peripheral, employs, for example, light cyan, light magenta, gray, or a similar color as light ink in addition to cyan, magenta, yellow, and black as dark ink and achieves print of higher image quality.
Typical image forming apparatuses have a plurality of print modes (image forming modes) where usage volume of dark ink and light ink are different for the same tone. The print mode includes, for example, a high image quality mode, a standard mode, and a high speed mode. The high image quality mode relatively consumes much usage volumes of light inks while the standard mode relatively consumes little usage volumes of light inks. The high speed mode does not use light inks and uses darks ink only.
Selecting these print modes reduces usage volumes of light inks. Additionally, replacing the usage volume of light ink by the usage volume of dark ink, image degradation can be reduced while reducing the total ink usage volume.
Some of the typical image forming apparatuses have a function of save mode. The save mode reduces usage volumes of dark/light inks at a specified proportion and controls the proportion of reduction of dark/light inks. This further reduces the total ink usage volume while minimizing image degradation.
However, the save mode does not consider a unit price of dark/light ink. Therefore, even if the total ink usage volume can be reduced, the total ink costs for print may not hardly change.
For a plurality of print modes, for example, as illustrated in FIGS. 12A to 12C and FIG. 13, the total ink usage volume in the high image quality mode may be tremendously increased or decreased compared with the total ink usage volume in the standard mode and the high speed mode.
FIGS. 12A to 12C are graphs illustrating usage volumes of dark/light inks in each print mode. FIG. 13 illustrates extraction of the total ink usage volumes of dark/light inks from the graph in FIGS. 12A to 12C. In FIG. 13, the solid line indicates the total ink usage volume in each ordinary print mode in a mode other than the save mode while the dashed line indicates the total ink usage volume in each print mode in the save mode.
In this case, even if the high image quality mode is set to the save mode, as illustrated by the dashed line in FIG. 13, the total ink usage volume in the high image quality mode may be larger than the total ink usage volume of the ordinary standard mode and high speed mode that are not in the save mode in a region R1. In contrast, even if the standard mode and the high speed mode are set to the save mode, the total ink usage volume may be larger than the total ink usage volume of the ordinary high image quality mode that is not in the save mode in a region R2.
In view of this, even if any of the print modes are set to the save mode, the total ink usage volume is reduced in other print modes not in the save mode depending on a tone. Consequently, this may reduce the total ink cost.